28389447 has 18 divisors (see below), whose sum is σ = 42591848. Its totient is φ = 18921924.

The previous prime is 28389409. The next prime is 28389467. The reversal of 28389447 is 74498382.

It is not a de Polignac number, because 28389447 - 2¹⁴ = 28373063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28389407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4398 + ... + 8724.

Almost surely, 2^28389447 is an apocalyptic number.

28389447 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28389447 is a deficient number, since it is larger than the sum of its proper divisors (14202401).

28389447 is an frugal number, since it uses more digits than its factorization.

28389447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4351 (or 4330 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 28389447 is about 5328.1748282128. The cubic root of 28389447 is about 305.0602657943.

The spelling of 28389447 in words is "twenty-eight million, three hundred eighty-nine thousand, four hundred forty-seven".